JSFiddle - React, Tailwind, and code Playground

JavaScript

var
iframe = document.body.appendChild(document.createElement('iframe'));

iframe.style.cssText = 'border:10px solid';

var
iwindow = iframe.contentWindow,
idocument = iwindow.document;

idocument.body.style.cssText = 'background-color:red';

idocument.body.innerHTML = 'Hello, World!';